It’s just a Bezier specific issue with any vector path drawn, not a specific font issue.
The Arial capital ‘W’ is just a very obvious example. That’s why there are ‘miter limits’ and ‘join types’
Here an example where obviously a miter limit is applied

You see the effect on the upper left edge of the W.
Probably it’s a kind of ‘post process’ since outline text needs 2 strings stacked upon each other to work.